Interaction of licorice on glycyrrhizin pharmacokinetics.

Abstract

The effects of components of aqueous licorice root extract (LE) on the pharmacokinetics of glycyrrhizin (G) and glycyrrhetic acid (GA) were investigated in rats and humans. The aim of this work was to define the role of pharmacokinetics in G toxicity. In the procedure, G and GA were detected in biological fluids by means of recently improved HPLC methods. Significantly lower G and GA plasma levels were found in rats and humans treated with LE compared to the levels obtained with those in which G alone was administered. The pharmacokinetic curves showed significant differences in the areas under the plasma-time curve (AUC), Cmax, and Tmax parameters. The data obtained from urine samples are in agreement with the above results and confirm a reduced bioavailability of G present in LE compared to pure G. This should be attributed to the interaction during intestinal absorption between the G constituent and the several components in LE. The modified bioavailability could explain the various clinical adverse effects resulting from the chronic oral administration of G alone as opposed to LE. -Environ Health Perspect 102(Suppl 9): 65-68 (1994)

Profound difference of metabolic pharmacokinetics between pure glycyrrhizin and glycyrrhizin in licorice decoction

“…The metabolism and disposition of GZ in humans and in rats were described in several studies (Wang et al, 1994;Ching et al, 2001Ching et al, , 2002Ozaki et al, 1990;Cantelli-Forti et al, 1994). Previous studies suggested that GZ could be absorbed per se from small intestine and its active metabolite GA was then absorbed from the large intestine.…”

“…There were two previous studies reporting the pharmacokinetic difference between pure GZ and licorice in rats and humans (Cantelli-Forti et al, 1994;Ozaki et al, 1990). The results showed that the areas under curves (AUCs) and C max of GZ and GA after dosing with pure GZ were markedly higher than those after dosing with licorice in rats and humans.…”

Determination of glycyrrhetic acid after consumption of liquorice and application to a fatality

“…They showed a significantly better bioavailability of GL and GA from liquorice than from pure GL in rabbits. In contrast, Cantelli-Forti et al determined lower GL and GA levels in rats after administration of aqueous liquorice root compared with pure GL [27]. Krä [19].…”

Changes in Components, Glycyrrhizin and Glycyrrhetinic Acid, in RawGlycyrrhiza uralensisFisch, Modify Insulin Sensitizing and Insulinotropic Actions

“…Previous studies [19][20][21] reported that absorption of glycyrrhizin and glycyrrhetinic acid in humans, rabbits, rodents was confirmed by metabolic pharmacokinetics in serum using liquid chromatography-electrospray ionization-mass spectrometry or HPLC, after GR or GRP was consumed. Glycyrrhizin was absorbed per se from the small intestine, and its active metabolite glycyrrhetinic acid was then absorbed from the large intestine.…”